Carburetor



G. KINGSTON Aug. 21

CARBURETOR Filed Feb. l, 1925 all',

III

Patented Aug. 21, 1928.

UNITED STATES 1,681,410 PATENT OFFICE.

GEORGE KINGSTON, F KOKOMO, INDIANA, ASSIGNOR T0 KINGSTON PRODUCTS COR- PORATION, OF KOKOMO, INDIANA, A CORPORATION OF INDIANA.

CARBURETOR.

Application filed February l, 1923. Serial No. 616,331.

This invention relates to a carburetor and particularly to a carburetor which 1s providedy with improved air regulating means which assure etiicientoperation throughout 5- a varying range Aot' engine speeds. In the carburetor which I have provided, a proper supply of fuel mixture is assured to etect a smooth acceleration of an engine on which the carburetor is mounted under a variety of operating conditions..

It is an object ot' this invention to provide a carburetor wherein an automatic air regulating valve is goverened by indirectly created pressure diercntial.

1t is a further object oi this invention to provide a carburetor wherein air valve governing means present a large area to be Vacted upon by diiferentiall pressures.

Itfis also an object of this invention to provide a carburetor wherein the closed position ot' an automatic air valve may be adjusted and wherein the effective atn'iospheric pressure applied to govern the operation of the air valve and consequently the acceleration ot a motor on which the carburetor is mounted. may be varied. l

It is another object of this invention to provide an automatic air valve carburetor having automatic pressure releasing means 3U to permit a quick return of the air valve to closed position.

` lt is a further object of the invention to provide a carburetor wherein the low speed carbureting system is gradually rendered less I3 effective as the speed of the engine increases.

It is an important object of this invention to provide a carburetor which may be cheaply manufactured from durable material, which is easily'adjustable and which is economical and eifective throughout a wide range ot operating conditions. Y

Other and further important objects of the present invention will be apparent from the disclosures in the speciticationand the accompanying drawings.

The invention (in a preferred form) is shown on the drawings and hereinafter more fully described. j

On the drawings:

Figure 1 is a central vertical section, with parts in elevation, through a carburetor embodying the principles ot this invention.

.Figure 2 is an enlarged fragmentary detail Asection, with parts in elevation7 showing .35 the air valve regulating means.

-iil

As shown on the drawings:

The reference numeral 1 indicates a carburetor casing which is preferably formed of cast'metal and which is provided with an air inlet 2 and a mixing chamber 3. Discharge or carbureted air from the mixing chamber is controlled by a usual butterfiy throttle valve 4 which is pivotally mounted in the casing 1 and adapted to be operated from the exterior of the carburetor in the usual manner, through a lever 5. A suitable fiange 8 is provided on the casing 1 outside the throttle valve 4 to atord a connection to an engine manifold in the usual manner. Extending downwardly from the floor of the casing 1, beneath the mixing chamber 3 and integral with said casing 1, is a pas saged projecting member 6, the lower..end 7 ot' which is reduced and externally threaded. Engaged over the reduced and threaded portion 7 of the'member 6 and making a tight joint with a seat formed on the outside ot the floor of the. casing 1 is a cup member 9 which ati'ords a fuel supply chamber and lwhich is secured in position relative to the casing 1 by means of a nut 10 engaged on the threaded portion 7 outside said cup member and acting to torce the same against a flange 11 formed on the member 6 adjacent said threaded portion. a suitable gasket 12 being preferably interposed between the inside ot the cup member 9 and said flange or shoulder 11.

A fuel inlet to the mixing chamber 3 is aiorded by a passage 17 formed in the member 6, an open ended tubular member 18 being mounted in the floor of the easing 1 at the upper end of said passage 17 and projecting t'or a short distance into said mixinv chamber 3. The upper-end of the passage 17 is enlarged to communicate with the passage in the tubular member 18 and may be regulated by a needle valve 19 which is adjustably mountedin a member 20 threaded in the upper side of the casing and which is adapted to be rotated to eii'ect the vertical adjustment thereof by means of a" knurled nut 21 secured to the outer end thereof. Surrounding the needle valve 19 is a tubular member 22 which is secured in the upper side ot the casing 1 and the lower open end of which extends into the open end of the tubular member 18. Said tubular member 22 is of such diameter relative to the t-ubular member 18 that a space is afforded therebetween and said tubular members may either be permanently adjusted in proper relative position when the carburetor is fitted, or they may be mounted in the casing 1 by screwing the same therein, in the manner shown in the drawing. Consequently, by inserting tubular members of dierent relative diameters, thel space therebetween may be varied. A depression is formed in the floor of the casing 1 around the tubular member 18, and in order to prevent flooding, an overflow passage 23 is formed in the member 6, a tube 24 secured in the upper end of said overflow )assage 23 projecting upwardly for a short t istance into the mixing chamber 3. A passage 25 is formed in the casing 1 affording communication between the air inlet 2 and the interior of the tubular member 22.

As will be noted from an examination of Figure 1, the mouth of the passage 25 opens downwardly into the air inlet 2, and formed in the casing l inside the mouth of said passage is an annular seat 26 which defines the main air passage from the air inlet 2 into the mixing chamber 3. Threaded in an aperture in the casing l and extending into the air inlet 2 is a horizontal sleeve 27 in which is slidably mounted a tube or sleeve 28, the open inner end of which communicates with the mixing chamber 3. Supported on the inner end of said tubular member 28 is a conical open end air valve 29, the outer face of which is adapted to coact with the.

seat 26 to control the flow of air from the inlet 2 into the mixing chamber 3. An integral dished flanged member 30 formed on the casing l' adjacent the inlet 2 has an outwardly dished flanged cover 31 threaded thereon and secured between the outer edges of said flange 30 and cover 3l is the vulcanized fabric diaphragm 32 which divides the compartment afforded between the flange 30 and cover 31 into chambers 33 and 34. The end of the tubular member 28 is made solid and externally threaded as indicated at 35, said threaded portion 35 extending through the center ot the diaphragm 32, said diaphragm being secured between a dished washer 36 threaded on said portion 35 and abutting the shoulder at the inner end thereof and a hexagonal flanged nut 37 screwed on said threaded portion on the outside of said diaphragm. In order to assure a tight connection between the outer edge of the diaphragm and the flange 30 and cover 3l an annular rounded projecting boss 38 is preferably formed on the face of the flange 30 near the periphery thereof. The air valve 29 is normally forced toward the seat 26 and the diaphragm 32 is normally held outwardly by means of a relatively strong helical spring 39 which is engaged between the dished washer 36 and a shoulder afforded by an enlarged portion 40 on the sleeve 27.

Communication between the interior of the tubular member 28 and consequently between the chamber 33 and the mixing chamber 3 is afforded by a series of radial passages 41 formed in said tubular member and extending from the interior thereof into communication with the chamber 33.

The inside of the cover' 31 is recessed at the center thereof to allow for movement of the nut 37 and extending outwardly from said central portion of' the cover is an integral boss 42 which is passaged and internally threaded to receive a threaded sleej'e having an adjusting head 44 thereon. The inner end of said sleeve 43 affords a stop for the threaded meluber 35 and uut 37 and consequently acts to limit the .outward movement of the diaphragm 3 The Sleeve 43 is internally threaded and the inner end of the passage therein is reduced, as shown at 45, to afford a seat for the valve member 4G, the hollow stem 47 of which is threaded for engagement with the internal threads in the sleeve 43. Said hollow stem 47 is split as indicated at 48 to allow of the insertion of a suitable tool for adjustment thereof and to afford a certain resiliency thereto which causes the sleeve to be automatically loclred in adjusted position, and the inner' end of the passage therethrough communicates with lateral passages 49 which extend to the outer face of the valve 4G. A tight joint between the boss 42 and the sleeve 43 is afforded by a gland nut 50 which is engaged on the external threads on said boss and acts to secure a suitable packing 51 between the outer end of the boss and the sleeve 43. In order to permit a rapid outward movement of the diaphragm to close the air valve 29, a release aperture 52 is formed therein, said aperture 52 being closed during the inward movement of the diaphragm by a spring pressed ball check valve 53 mounted in a casing 54 as shown in Figure 1. A small drain passage 55 is formed in the flange 3() near the bottom of the chamber 33 to permit condensed fuel which may accumulate in said chamber to drain therefrom. During the existence of subatmospheric pressure in the chamber 33 the rush of air through said passage 55 also acts to return any such fuel back into the mixing chamber 3.

The operation is as follows:

At low engine speeds, a part of the air to be carbureted is drawn through the passage 25 and downwardly through the tubular member 22 where it is carbureted by fuel drawn upwardly through the tubular member 18. Thisair is supplemented by air flowing past the valve 29 and adjustment of the valve 29 may serve as a convenient means of final low speed adjustment of the carburetor by the user thereof. The amount of fuel flowing through the passage 17 may of course be regulated by the needle valve 19 createdin the chamber 33 through the communication with the mixing chamber affordf ed by the tubular member 28 and the paslsages 41, is suiicient to overcome the action ber 34. The eliective diii'erence in pressure between the chambers 33 and 34 may of course be regulated by adjustment of the valve 46 which regulates the yamount of air admitted to the chamber 34 and consequently controls the time element of movement of the air valve 29.

The operation and action of the valve 46 may be best understood by a description ot' the action thereof lunder two extreme conditions. It will befapparent that as said valve is closed upon its seat sothat no air is admitted to the chamber 34, that the air valve 29 cannot move away from its seat except as the pressure differential may attenuate the air, thus-causing the airyalve to leave its seat a very slight amount, if at all, after which the pressure in both chambers 33 and 34 will be in equilibrium, preventing the full operation of the air valve. This is one extreme condition. Viewing the operation from the standpoint of Vthe opposite extreme condition, with Vthe valve 46 entirely ofi" its seat and admitting a free How ot air to the chamber 34, a very rapid pressure differential will be created causlng the air'valve 29 to be moved outwardly very rapidly. By reason of the existence of the two extremes above pointed out, it will be. apparent that by proper inward adjustment of the valve 46 it will be` possible to control the movement of the air valve 29 with re# gard to a time period. In this manner it is possible to compensate for the difference in. inertia between air and liquid fuel by retarding the air flow through a proper adjustment of the valve 46.

. Upon the creation of a sulicient pressurel differential between the chambers 33 and 34,

the diaphragm 32 will begin an inward wmovement, thus opening the air valve 29 and reduce the iow of air throu h said passage and through the tube 22, andg at highengine speeds a large part of the air is dra-wn into the mixing chamber past the air valve 29. When the engine speed is reduced by closing the throttle valve 4 and the subatrospheric' pressure existing in the chamber 33 has decreased, the spring 39 acts to move the diaphragm 32 outwardly, thus tending to close the air valve 29. The aperture or passage 52 aliords a relief .forthe chamber 34 during this outward movement of the diaphragm 32, the spring pressed check valve '.53 readily opening when the diaphragm is moving in outward direction. The provision of the check valve 53 is also a valuable feature when considered in connection -tn the operation of the carburetor du.ing the starting vof a cool engine. Whenthe engine is cold, the fuel mixture of course has a tendency to leanness. For this reason, if an endeavor is made to accelerate the motor when cold, there will not be a suilicient supply .of fuel to continue operation of the motor and back firing through the carburetor will ensue. When this occurs, the back pressure on the air valve and in the chamber 33 will act toi force the air valve rapidly to outward after seating because of the requirement of a 'greater volume, theretore producing the richer mixture required for accel- 'itslseat The air valve immediately moves action is of value because without it there, .Y

would be a possibility of the engine speeding up until the mixture became so lean that the enginewould entirely stop running.

It will be noted that 'the provision of a large area diaphragm makes possible the use of a relatively strong helical spring 39 and by makino` the diaphragm of vulcanized fabric or similar material, a larger range of air valve movement is possible than would be the case where a metal diaphragm would be used. v

It will be apparent from the foregoing description that this invention rovides a carburetor which may be accurate y adjusted to 'meet varying operating conditions and one which is compact, economical and which does not easily get out of adjustment.

It will also be. apparent that the construction provides a carburetor wherein the transition from the low speedsto the high speed carburetin system 1s a gradual one and wherein t ere is no noticeable transfer point. l e

I am aware that numerous details of construction may be varied through a wide range without departing'from thepgirnciples of this invention, and I therefore do not pur pose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention:

1. In a carburetor, a valve for controlling the main air passage to the mixing chamber embodying a slidably mounted sleeve supporting the valve, a casin supporting said sleeve, a diaphragm secure to the sleeve and closing the casing, resilient means tending to hold the diaphragm outwardly and the valve in closed position, and a passage through the sleeve affording communication between the mixing'chamber and the inner side of the diaphragm whereby a differential sub-atmospheric or back-lire pressure may be ap lied thereto.

2. n a carburetor, a valve for controlling the main air passage to the mixin chamber embodying a slidably mounted s eeve supporting the valve, a casing supporting said sleeve, a diaphragm secured to the sleeve and closing the casing, a passaged cover on the casing outside the diaphragm, means tend' ing to hold the diaphragm outwardly and the valve in closed position, and a passage Y through the sleeve affording communication between the mixing chamber and the inner side of the diaphragm, whereby a sub-atmospherie or back-lire pressure is applied to said inner side of the diaphragm.

3. In a carburetor, a valve for controlling the main air passage to the mixing chamber embodying slidably mounted sleeve supporting'the valve, a casin supporting said sleeve, a diaphragm secured to the sleeve and closing the casing, a passaged cover on the casing outside the diaphragm, means for regulating the flow of air through the passage in the cover, resilient means tending to hold the diaphragm outwardly and the valve iu closed position, and a passage through the sleeve affording communication between the mixing chamber and the inner side of the diaphragm, whereby a sub-atmos heric or back-tire `pressure may be create on said inner side of the diaphragm.

4. In a carburetor, a valve for controlling the main air passage to the mixing chamber embodying a hollow open-end movably mounted sleeve communicating with the 1,ee1,41ol

mixing chamber and supporting the valve, a casing supporting said sleeve, a diaphragm secured to the sleeve and closing the casing, resilient means tending to hold the diaphragm outwardly and the valve in closed position, and radial passages in the sleeve affording communication from the interior thereof to the inner side of the diaphragm to permit access of either sub-atmospheric or back-fire ressure to said diaphragm.

5. In a car uretor, having a mixing chamber, a fuel inlet, a main air passage to the mixing chamber, and, a throttle controlling the outlet from the mixing chamber, a valve controlling the said main air passage, an open-end tube surrounding the fuel inlet, a second open-end tube extending downwardly into said first tube and spaced therefrom, and a passage affording communication between the upper end of said second tube and the air inlet extending around the valve controlling the air inlet to the mixing chamber.

G. In a carburetor, having a mixing chamber, a fuel inlet, a main air passage to the mixing chamber and a throttle controlling the outlet from the mixing chamber, a movably mounted valve controllin the said main air assage, an open-en tube surrounding t e fuel inlet, a second open-end tube extending downwardly into said first tube and spaced therefrom, and a passage having its mouth closely adjacent the valve and communicating with the said second tube, the mouth of said passage being so positioned relative to the valve that any considerable flow of air past the valve tends to check the flow of air through said passage.

7. In a carburetor, a mixing chamber` a fuel inlet, a main air passage to the mixing chamber, a throttle controlling the outlet from the mixing chamber, a pressure operated valve controlling said main air passage, a passage of constant size regardless ot' suction leading around and above said main air passage valve to the fuel inlet, and adjustable means to change the position of the outlet from said passage relative to the fuel inlet.

In testimony whereof I have hereunto subscribed my name.'

GEORGE KINGSTON. 

